Such circulation apparatus is used in swimming pools, jacuzzis and the like demanding strong flows or high volumes of water for filtering. Commensurately powerful pumps are required to provide the related high circulating flows.
A fairly coarse sieve to catch substantial parts (for instance filaments, twigs, tools etc.) that endanger these pumps is usually mounted on their suction side. Accordingly such substantial parts are precluded from entering the pump and the circulation apparatus offers long service life. Fine filtering also may be provided, the fine filter usually being mounted on the pump's output side, because the pump's [absolute] pressure output typically being larger than the [absolute] suction input and the filter media entailing an [absolute] pressure drop larger than the [absolute] suction input of the pump.
The German patent document DE 76 276 66 U1 discloses a bath/pool circulation apparatus comprising a pump powered by a drive. A filter section is configured on the pump's suction side and consists of a housing and a cover. The cover is fixed in place by two wingnuts.
The U.S. Pat. No. 299,143 S also shows such a design, however the cover is fitted with two mechanical stops, each being a screw fitted with a knob.
The present state of the art incurs the drawback that the basket collecting the detritus/dirt will soil rapidly but nevertheless is not cleaned regularly because of its handling. This feature increases the flow impedance, entailing moving less water for a given original pump output.
In fact, the time required for cleaning is an obstacle to operation. The state of the art's locking by means of screws entails long cleaning times. After loosening the screws, the cover too must be removed as a whole. In view of the typical ambient conditions, this cover then usually is deposited on a soiled surface. Adhering dirt must be removed—at least on the sealing side—before said cover may be reinstalled later. Such reinstallation in turn requires first properly positioning the cover, while the force sealing it is determined by the depth of engagement of the affixing elements. The user in this process must to screw-in the two affixing elements in alternating manner to assure uniform compression to attain sealing between the cover and the housing. Also necessity of tools typically hampers regular cleaning.
A further drawback of the state of the art requires the user to touch the water inside the housing when removing the filter set therein. The user finds the existing soiling distasteful. Worse, insects still alive such as wasps and bees may be found in such locations and sting the user removing the filter.
Said filter being very heavy, it is extricated from the housing only with substantially difficulty. It is located operationally so deep inside said housing as to be accessible only with difficulty and must be emptied by slow extraction before being fully removed. The more soiled the filter, the longer it takes to drain its water and hence its removal. This chore must be carried out by a bent-over person over during said time interval.